Circle squarer



Jan. 20, 1953 A. s. RAETTIG 2,625,740 CIRCLE SQUARER Filed May 8, 1951 2 SHEETS-SHEET 2 INVENTOR. ADELE 5. 24.57776 wwuwm Patented Jan. 20, 1953 UNITED STATES QF-EICE :CIRCLE SQUARER Ade e aetti I-HQB K I I J r; Application May 8, 1951i Seria-IiNo. 225,117

5 Claims.

This invention relates to a device or circlesquarer for converting the area of a circle into a square of equal area or conversely, and the-cir- .cumference of a circleinto the perimeter of a square of equal length or conversely.

In various engineering problems,-it fre uently becomes necessary tolay put asquare having an area equal to'thatof a given circle orto lay out a circle having anarea equal to that of a given square. Moreover; the rearrangement of-the circumference of a given circle into the perimeter of a square of equal length is encountered as -well on the converseofthe problem. a At present, such problems involve :mathematical calculations in which the indefinite value ctr is ever present and finally actual constructionwhich istime consuming and resulting in iigures having a'degree of accuracy dependent upon the quality and/or 1 condition of the instruments used and the skill of the operator.

Itis an object of the instantinvention to facilitate the work of mathematicians, engineers, and architects, and-of students in said fields.

Other objects of the instant inventionwill become apparent in the course of the;following specification.

In the accomplishment of these objectives; the device is constituted of atransparentbody of any convenient size in. which; a'square opening-has been formed. Correlated with the square opening and at one side thereof are two right angle .triangles inscribed .on the transparent body. The

vbase of one ofcthe right angle triangles is onthe I out square-whenconverting the area of a" given circle into a square of equal"; area or; conversely.

The second right angle triangle is used incoaction with the cutoutsquare when-converting the circumference ofa circle into the perimeter of a square of equal length-or conversely. An

inverted T-shapecl-guideiis provided so that whenthe center of a given circle has been located on the perpendicular 0f: the first right triangle and the circumference intersects --the hypotenuse thereof, :the square"ofeequal- -area --is directly formed in the cut out square-by the-guide. con- .yer selyiyiby. locating,- a-given. square in coaction cwiththe' guide inthe cut out-square, the center rand radius of a. circle ofnequal area is quickly ,.found on, the first vtriangle. The second triangle ;is utilized in conjunction with the guide and cut out square .toconvert. the circumference of a circle.into.-the perimeter ofa square. of. equal I ..1engthandconversely.

The invention...will. appear. more clearly from the. following. detailed. description when taken in rconnectionqwith. the accompanying drawings .showingby. way pf..-example a preferred embodi- .ment of the inventive idea.

.ln the drawings: J'Figure 1 isa top plan view of the device constructed in accordance with the' principles of this invention.

'Eigure 2, is, at op plan view of the guidev utilized in conjunction with ,thedevice-shown in Eigure 1. Figure. 3.,is a diagrammaticfview of. a quad- ..rant of acircle converted} into a rectangle V of equal. a e

Figure 4 isa diagrammatic :viewof four ofthe rectangles shown inyFigure 3 arranged-inz the order, ota square but having a space over at the center.

"-Eigure; 5*is a" diagrammatic view'of a square 'equal in-area to "four ofithe rectanglesshown in Figure 3 but without a 'space'oVerI as shown in Figure 4.

{Figure- 6 is'a diagrammatic view of an eighth of a circle witha-ra'dius of 'mmthe area of which ismadeup of layers with progressively decreasing arcs (eighthsofcircumferences) Figure 'L-isa-diagrammatic view of four of the rectangles shown-in Figure 3 arranged oneabove the-other and having anarea equal to a circle of which Figure 3 is one quadrant and in which the surnof the vertical lines is equal to the circum- ---ference.

-= Figure- 8":is a diagrammatic-view of asquare Hhaving aperimeterrequalto the sum of the vertic'al' linesof-Figure7 or the perimeter of a square "which is; equal to' the circumference of a circle of w ich-Fi i ows Qneiquadr n s re' 9 s; a n a v wer. he device an uid "showing the ,mefthfidfor. converting; the area of a .circIeinto a square ofequal. area.

Figure lllis, a plan .viewe-ofthe device and guide h w n h m h d v mrr;t m; r sthe; ci

r ferencerof a: circle ;into.;the perimeter ofza square 0f-=equa1'1en het rring now. ingreater detail to :the'drawings rawherezlike reference 'nnmeralsQindicate like parts, reference-rnumeral 10 indi'cates .the transparent body of the device or circle-squarer, and II the guide coacting with the body.

The device III is a flat body of any suitable transparent material having a base I4 and an edge 28 forming an angle of 45 therewith. In the body is a square opening I2 with sides equal to the square wyzx in Figure 5 and in which the base I3 may be parallel to the base I4 of the device IU. At the left of the square opening I2, as viewed in Figure 1, are the right angle triangles I5 and IS, the top of the perpendicular of each of which is along the top edge of the square when projected, the top edge projected being at 90 to the perpendiculars. The base ab of the 7 triangle I5 lies along the line of the base I 3 of the.

square opening I2 extended and is equal in length to the base of the rectangle mnoq (Fig. 3) described later. The perpendicular cb of the triangle I5 is equal in length to one side of the square opening I2. The perpendicular cc of the right angle triangle I6 is superposed on the perpendicular be, starting at the top (Fig. l) and extending downwardly toward the base ab of the triangle I5 for a distance equal to twice or in Figure 6 or twice no in Figure 3 or to one side of the square in Figure 8. The base de of the triangle I6 is equal in length to the base ab of the triangle I5 so that the hypotenuse do of the triangle IB is less than the hypotenuse ac of the triangle I5 and the angle dce of the triangle I6 greater than the angle acb of the triangle I5.

Coacting with the inscribed triangles and cut out square of the transparent body I is a guide II of any suitable material. The guide II is in the form of an inverted T- with a horizontal member 26 and an upright member 21 and so constructed that the upper edges fir and k (Fig. 2) are in a straight line within the limits of construction and the angle Zky' a right angle. The left end of the horizontal member 26, that is, the edge g (Fig. 2), is formed at an angle of 45 with the lower edge gh, so that when the edge gf slides along the edge 28 (Fig. 1) the open square space will always show true squares. The guide may be provided with a hand grip (not shown).

The theory upon which, the inscribed right angle triangles l and I6 and cut out square I2 are constructed is as follows:

Any quadrant of a circle mnp (Fig. 3) having a radius mn may be converted into a rectangle,

mnoq of equal area by constructing on the radius mn of the quadrant a diagonal mo to the perpen dicular 7210 where the angle nmo is equal to approximately 37 45' and completing the figure.

There are several methods of finding the position of this diagonal. One is to locate the line running through the center of gravity of the quadrant from the 122 end which can be done by suspension and plumb-line Or by equalizing the weight on twoiiat scales in juxtaposition. .Ex-

periment with the latter, placed angle nmo at 37 45, subject to'correction. Another method is to take a quadrant of proper substance and thickness 1., melt it, and recast the melted material in a rectangular mold with open top and base measurement ofjthe product of mn and t. 'The height of the resulting'shape corresponds to no. A line is drawn on the flat side from m to 0, for

the diagonal, and angle nmo measured.

To convert the rectangle mnoq, representing the area of the circular quadrant mnp into a square having an area equal to that of a circle of which the quadrant mnp is one-fourth, rectangles 29, 30, 3| and 32, identical .with" the rectangle vof F ur a a ran d to formasquare. as shown in Figure 4. However, while the resulting Figure 4 is a square there is a square space stun over in the center so that the sides of the 50 arranged square must be reduced to eliminate the residual area over stuv. Since the square on the hypotenuse of any right angle triangle is equal to the sum of the squares on the other two sides, a square (Fig. 5) is constructed on the perpendicular was of the right angle triangle own: which has a hypotenuse equal to theside of the square formed by the rectangles and shown in Figure 4 and a base equal to a side st of the central square space over stun. Thus, a square having sides equal to war (Fig. 5) will be equivalent in area to the four rectangles arranged as shown in Figure 4 with the central space over eliminated or the square wyzx will have an area equal to a circle of which (radius=mn (Fig. 3)).

mnp (Fig. 3) is one quadrant.

By construction, the cut out square I2 (Fig. 1) is made equal to the square wear of Figure 5. Also by construction, the base ab of the triangle I5 is made equal to the base mn (Fig. 3) of the rectangle mnoq and as shown a circle with center at b (Fig. 1) and radius ab will form the corresponding cut out square I2. By connecting the points a and c of the triangle I5 a series of radii between the limits of c and ab are found which when converted to an equivalent square by the guide II as later shown will give a series of squares the areas of which correspond to the radii of the circles between the aforesaid limits of c and ab.

Figure 6 shows two horizontal lines parallel to each other and separated by distance r To the left of the central vertical is one-eighth of a circle with radius r. The one-eighth or 45 section may be assumed a portion of a fiat circular plate from which when held upright, perpendicular to the paper, there is rolled oil the 45 arcs length on the upper horizontal line from o, landing at ac. Hence, or is therefore one-eighth of the circumference of a circle of mm or 00 radius. The area of the section coo' may be considered as composed of flexible layers, each with its own circumference. The outermost is the determining factor of 00; Inwardly toward the center, the A; circumferences become progressively shorter to disappear at o. ;By connecting a: and c, the triangle cor equal to the area coo is formed. The triangle car is a right-angle triangle and since the right-angle triangle mno equals the same area the triangle e0a2=mno, and ox=no=% of the circumference.

If one of the sides 35, 36, 31 or 38 of the square shown in Figure 8, dimensioned as described above, is laid off on the perpendicular ch as ce (Fig. 1) and the base ed is constructed perpendicular thereto and equal to the radius mn of the are shown in Figure 3 and the upper edge flc of the guide II is placed along the line de with the edge jg on edge 23, a square will be formed in the cut out square I2 which has a perimeter equal to that of the circumference of a circle of which the arc mp is one quarter. In a similar manner, by drawing thehypotenuse do the circumference to any circle having a radius between the limits of the radius de (equal to mn in Figure 3) and 0 may be converted into the perimeter of a square of equal length. Contrariwise, with a circles perimeter given in length, the circles radius can be found by working backwards from the square space, taking one-fourth f nding the radius in. trian le. I 6.

The operation with the deviceor cirole-squarer is as follows:

Suppose it is desired to convert the area of the circlegts asshown'in'ifigure 9 into. a square of ,eq ale e e Thegidevice Illqisjplaced over the circle 39 until the center {i2 thereof lies o s h e ti a .v est th t ia .1 a the radiusfits horizontally in triangle I 5. The guide I I .is then plac ed' onthe device Iii with the upper edeefl of he uide pa s throu h. the poi t 42 and the lpointfdfii, that is, wherefthe circumference ofthe circle 39 cuts the hypotenuse, ac,

e., the end ur n horizontal radius in the triangle'IE and. with the aneularend. gfv of th guidealong; the edge ,28 of the device Ii] sothat the upperedge ky" will,be parallel'with the base I3 of the cut outv square [12. I Then, the square icziab iormedby the guide Il in the cutout H square] 2 will have an area equal to the area of the circle '39.

' Conversely, suppose it is desired to construct a circletil havin aQarea equaI to a given square .kj'a'b', with the edges ja', and afbi over two fadjacent sides of thesquareand the guide, II

over :the other two sides as shown iniFigure 9,

- it is only necessary to follow along theledge fit jtoxfind Where the same intersects the perpendicularbc which willbe thecenter of the circle and where-the same edge intersects the hypotenuse ac which will give theradius ofthe circle of equivalent area;

; Suppose further that itis desired toconstruct a square having, a perimeter equal to that of the circumference of the circle ii in Figure 10. The

device I9 issuperposed on'the circle 54 until the center iallsalong the perpendicular cc of the triangle i6 and its radius fits horizontally in the triangle 1%. The guide I is thenplacedon the ,deviceifi with the end .gj along the edge,23 of the .device, and the upper edge through they point h v and the point cl. The' s-quare c'd'ef' formed by the guide I l,in coaction with the cut out square I2 v.will haye a perimeter equalgto', the circumierenceof theeircle A l. in a similar manner,

;. tion and not by wayof limitation and that the structures wer .descr be ar ,.s iec to wi v c a mod fisai bn :..w t de r from the-scope or intent of the invention, all of which variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A device for converting the areas of circles within predetermined limits into squares of equal area or conversely, the device comprising a flat transparent body, the body having a right angle triangle formed thereon, the base of the triangle being equal in length to the radius of the circle of maximum limit and the perpendicular of the triangle being equal in length to the side of a square having an area equal to the area of the circle of maximum limit, the body further having a square opening formed therein, one side of the square opening having the upper end thereof on a line which when projected will intersect the top of the perpendicular of the triangle at 90 and the base of the square opening being aligned w t the a e t rian l lm an l-i tra sf rring any point on the, perpendicular of the triangle to the square opening along a line parallel to the base of thetriangle and intersecting at least one of the sidesof the square opening, the transferred point being spaced from thepoint of intersection a distance equal to the distance from the top of the perpendicular of the triangle to the point thereon being transferred, and means for inscribing a square in the square opening using the transferred point. as one corner of the inscribed square and one of the corners of the square opening along the upper edge thereof as theopposite corner-oi the inscribed square.

2. A device for converting theareas of circles within predetermined limitsinto squares of equal area or conversely in combination with a guide, the device comprising a hat transparent body, the body havingat least one straight angle edge and a second straight angle edge inclined to the first at an angle of e53 the transparent body further having a-right angle triangle formedthereon, the base of the triangle being parallel to the first straight angle edge and spaced from the second and equal in length to the radius or" the circle of maximum limit, the perpendicular of the triangle being at the end of the base most remote from the second straight angle edge and equal in length to the side of a square having an areaequal to the area of the circle of maximum limit; the body further having a square opening formed therein, the ,opening being spacedfrom the triangle on the side of the perpendicularthereof and with the base of the square aligned with the base of the triangle and equal in length to the perpendicular of the-trianglerthe device further ccmprisi ga guide for thetransparent body, the guide comprising an inverted T -shaped member, the inverted T-shaped member comprising an upright straight edge portion and a horizontal straight edge portion.disposed'intermediate the ends thereof at the base of-the upright portion, the center lines of the portions forming an angle of with each other, one end of the horizontal portion being inclined at. {15 to thecenter line thereof and coinciding with the inclined edge of the transparent body when the edge of, the horizontal portion most remotefrorn the first edge of the body issuperposed on the bases of the triangle and the square and the edge of the upright portion most remote from thetriangle is superposed on the uprightedge oi the squ are adjacent the triangle.

3. A device for converting the circumierences of circles Within precleterrnined limits into the perimeters of squares of equal length or conversely, the device comprising a fiat transparent body, the body having a right angle triangle formed thereon, the base of the triangle being equal in length to the radius of the circle of maximum limit, the perpendicular of the right triangle being equal in length to twice the length of one side of a rectangle equal in area to the area of a quadrant of the circle of maximum limit Where the other side of the rectangle is equal to the radius of the circle of maximum limit, the transparent body further having a square opening formed therein, the upper edge of the square opening being on a line which when projected will intersect the top of the perpendicular of the triangle at 90 and the sides of the square opening extending downwardly at least to the bottom of and in spaced parallel arrangement with the perpendicular of the triangle, means for transferring any point on the perpendicular of the triangleto the square opening along a line at 90 to said perpendicular at said point and intersecting at least one of the sides of the square opening, the transferred point being spaced from the point of intersection a distance equal to the distance from the top of the perpendicular of the triangle to the point thereon being transferred, and means for inscribing a square in the square opening using the transferred point as one corner of the inscribed square and. one of the corners of the square opening along the upper edge thereof as the opposite corner of the inscribed square.

4. A device for converting the circumferences of circles within predetermined limits into the perimeters of squares of equal length or conversely in combination with a guide, the device comprising a flat transparent body, the body having at least one straight angle edge and a second straight angle edge inclined to the first at an angle of 45 the transparent body further having a right angle triangle formed thereon, the base of the triangle being parallel to the first straight angle edge and spaced from the second and equal in length to the radius of the circle of maximum limit, the perpendicular of the triangle being equal in length to twice a principal dimension of a rectangle equal in area to the area of a quadrant of the circle of maximum limit where the other principal dimension of the rectangle is equal to the radius of the circle of maximum limit; the transparent body further having a square opening formed therein, the opening being spaced from the right triangle on the side of the perpendicular thereof with the upper side of the square aligned with the upper apex of the triangle and perpendicular in direction to the perpendicular of the triangle; the device further comprising an inverted T-shaped guide slidable over the face of the transparent body, the guide comprising an upright straight edge portion and a horizontal straight edge portion disposed intermediate the ends thereof at the base of the upright portion, the center lines of the portions forming an angle of 90 with each other, one end of the horizontal portion being inclined at 45 to the center line thereof and coinciding with the inclined edge of the transparent body when the edge of the horizontal portion most remote from the first straight angle edge of the body is superposed on the base of the triangle and the edge of the upright portion most remote from the triangle is a distance equal to the length of said perpendicular from the side of the square remote from the triangle.

5. A device for converting the areas of circles within predetermined limits into squares of equal area and the circumferences of the circles into the perimeters of squares of equal length or conversely in combination with a guide; the device comprising a flat transparent body having two straight angle edges inclined at to each other; the body further having a right angle triangle formed thereon, the base of the triangl being parallel to one of the straight angle edges and spaced from the other and equal in length to the radius of the circle of maximum limit, the perpendicular of the triangle being at the end of the base most remote from the inclined edge of the body and equal in length to the side of a square having an area equal to the area of the circle of maximum limit; the body further having a square opening formed therein, the opening being spaced from the triangle on the side of the perpendicular thereof with the base of the square aligned with the base of the triangle and equal in length to the perpendicular of the triangle; the body further having a second right angle triangle formed thereon, the perpendicular of the second triangle being superposed on the perpendicular of the first and extending downwardly from the top of the perpendicular of the first triangle toward the base thereof, the perpendicular of the second triangle being equal in length to twice a principal dimension of a rectangle equal in area to the area of a quadrant of the circle of maximum limit where the other principal dimension of the rectangle is equal to the radius of the circle of maximum limit, the base of the second triangle being spaced from and parallel to the base of the first and equal to the radius of the circle of maximum limit; the device comprising an inverted T-shaped guide for the transparent body, the guide comprising an upright straight edge portion and a horizontal straight edge portion disposed intermediate the ends thereof at the bottom of the upright portion and with the center lines of the portions at to each other, one end of the horizontal portion being angular and parallel with the inclined edge of the body when the edges of the horizontal portion of the guide are parallel to the bases of the triangles and the base ofthe square and the edges of the upright portion are parallel to the perpendiculars of the triangles.

ADELE S. RAETTIG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 808,511 Cochran Dec. 26, 1905 870,959 Hitchings Nov. 12, 1907 1,163,392 Cashmore Dec. 7, 1915 1,409,723 Jacob Mar. 14, 1922 

